Merge branch 'jc/maint-combine-diff-pre-context' into maint
[git] / config.c
1 /*
2  * GIT - The information manager from hell
3  *
4  * Copyright (C) Linus Torvalds, 2005
5  * Copyright (C) Johannes Schindelin, 2005
6  *
7  */
8 #include "cache.h"
9 #include "exec_cmd.h"
10
11 #define MAXNAME (256)
12
13 static FILE *config_file;
14 static const char *config_file_name;
15 static int config_linenr;
16 static int config_file_eof;
17 static int zlib_compression_seen;
18
19 static int get_next_char(void)
20 {
21         int c;
22         FILE *f;
23
24         c = '\n';
25         if ((f = config_file) != NULL) {
26                 c = fgetc(f);
27                 if (c == '\r') {
28                         /* DOS like systems */
29                         c = fgetc(f);
30                         if (c != '\n') {
31                                 ungetc(c, f);
32                                 c = '\r';
33                         }
34                 }
35                 if (c == '\n')
36                         config_linenr++;
37                 if (c == EOF) {
38                         config_file_eof = 1;
39                         c = '\n';
40                 }
41         }
42         return c;
43 }
44
45 static char *parse_value(void)
46 {
47         static char value[1024];
48         int quote = 0, comment = 0, len = 0, space = 0;
49
50         for (;;) {
51                 int c = get_next_char();
52                 if (len >= sizeof(value))
53                         return NULL;
54                 if (c == '\n') {
55                         if (quote)
56                                 return NULL;
57                         value[len] = 0;
58                         return value;
59                 }
60                 if (comment)
61                         continue;
62                 if (isspace(c) && !quote) {
63                         space = 1;
64                         continue;
65                 }
66                 if (!quote) {
67                         if (c == ';' || c == '#') {
68                                 comment = 1;
69                                 continue;
70                         }
71                 }
72                 if (space) {
73                         if (len)
74                                 value[len++] = ' ';
75                         space = 0;
76                 }
77                 if (c == '\\') {
78                         c = get_next_char();
79                         switch (c) {
80                         case '\n':
81                                 continue;
82                         case 't':
83                                 c = '\t';
84                                 break;
85                         case 'b':
86                                 c = '\b';
87                                 break;
88                         case 'n':
89                                 c = '\n';
90                                 break;
91                         /* Some characters escape as themselves */
92                         case '\\': case '"':
93                                 break;
94                         /* Reject unknown escape sequences */
95                         default:
96                                 return NULL;
97                         }
98                         value[len++] = c;
99                         continue;
100                 }
101                 if (c == '"') {
102                         quote = 1-quote;
103                         continue;
104                 }
105                 value[len++] = c;
106         }
107 }
108
109 static inline int iskeychar(int c)
110 {
111         return isalnum(c) || c == '-';
112 }
113
114 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
115 {
116         int c;
117         char *value;
118
119         /* Get the full name */
120         for (;;) {
121                 c = get_next_char();
122                 if (config_file_eof)
123                         break;
124                 if (!iskeychar(c))
125                         break;
126                 name[len++] = tolower(c);
127                 if (len >= MAXNAME)
128                         return -1;
129         }
130         name[len] = 0;
131         while (c == ' ' || c == '\t')
132                 c = get_next_char();
133
134         value = NULL;
135         if (c != '\n') {
136                 if (c != '=')
137                         return -1;
138                 value = parse_value();
139                 if (!value)
140                         return -1;
141         }
142         return fn(name, value, data);
143 }
144
145 static int get_extended_base_var(char *name, int baselen, int c)
146 {
147         do {
148                 if (c == '\n')
149                         return -1;
150                 c = get_next_char();
151         } while (isspace(c));
152
153         /* We require the format to be '[base "extension"]' */
154         if (c != '"')
155                 return -1;
156         name[baselen++] = '.';
157
158         for (;;) {
159                 int c = get_next_char();
160                 if (c == '\n')
161                         return -1;
162                 if (c == '"')
163                         break;
164                 if (c == '\\') {
165                         c = get_next_char();
166                         if (c == '\n')
167                                 return -1;
168                 }
169                 name[baselen++] = c;
170                 if (baselen > MAXNAME / 2)
171                         return -1;
172         }
173
174         /* Final ']' */
175         if (get_next_char() != ']')
176                 return -1;
177         return baselen;
178 }
179
180 static int get_base_var(char *name)
181 {
182         int baselen = 0;
183
184         for (;;) {
185                 int c = get_next_char();
186                 if (config_file_eof)
187                         return -1;
188                 if (c == ']')
189                         return baselen;
190                 if (isspace(c))
191                         return get_extended_base_var(name, baselen, c);
192                 if (!iskeychar(c) && c != '.')
193                         return -1;
194                 if (baselen > MAXNAME / 2)
195                         return -1;
196                 name[baselen++] = tolower(c);
197         }
198 }
199
200 static int git_parse_file(config_fn_t fn, void *data)
201 {
202         int comment = 0;
203         int baselen = 0;
204         static char var[MAXNAME];
205
206         for (;;) {
207                 int c = get_next_char();
208                 if (c == '\n') {
209                         if (config_file_eof)
210                                 return 0;
211                         comment = 0;
212                         continue;
213                 }
214                 if (comment || isspace(c))
215                         continue;
216                 if (c == '#' || c == ';') {
217                         comment = 1;
218                         continue;
219                 }
220                 if (c == '[') {
221                         baselen = get_base_var(var);
222                         if (baselen <= 0)
223                                 break;
224                         var[baselen++] = '.';
225                         var[baselen] = 0;
226                         continue;
227                 }
228                 if (!isalpha(c))
229                         break;
230                 var[baselen] = tolower(c);
231                 if (get_value(fn, data, var, baselen+1) < 0)
232                         break;
233         }
234         die("bad config file line %d in %s", config_linenr, config_file_name);
235 }
236
237 static int parse_unit_factor(const char *end, unsigned long *val)
238 {
239         if (!*end)
240                 return 1;
241         else if (!strcasecmp(end, "k")) {
242                 *val *= 1024;
243                 return 1;
244         }
245         else if (!strcasecmp(end, "m")) {
246                 *val *= 1024 * 1024;
247                 return 1;
248         }
249         else if (!strcasecmp(end, "g")) {
250                 *val *= 1024 * 1024 * 1024;
251                 return 1;
252         }
253         return 0;
254 }
255
256 int git_parse_long(const char *value, long *ret)
257 {
258         if (value && *value) {
259                 char *end;
260                 long val = strtol(value, &end, 0);
261                 unsigned long factor = 1;
262                 if (!parse_unit_factor(end, &factor))
263                         return 0;
264                 *ret = val * factor;
265                 return 1;
266         }
267         return 0;
268 }
269
270 int git_parse_ulong(const char *value, unsigned long *ret)
271 {
272         if (value && *value) {
273                 char *end;
274                 unsigned long val = strtoul(value, &end, 0);
275                 if (!parse_unit_factor(end, &val))
276                         return 0;
277                 *ret = val;
278                 return 1;
279         }
280         return 0;
281 }
282
283 static void die_bad_config(const char *name)
284 {
285         if (config_file_name)
286                 die("bad config value for '%s' in %s", name, config_file_name);
287         die("bad config value for '%s'", name);
288 }
289
290 int git_config_int(const char *name, const char *value)
291 {
292         long ret;
293         if (!git_parse_long(value, &ret))
294                 die_bad_config(name);
295         return ret;
296 }
297
298 unsigned long git_config_ulong(const char *name, const char *value)
299 {
300         unsigned long ret;
301         if (!git_parse_ulong(value, &ret))
302                 die_bad_config(name);
303         return ret;
304 }
305
306 int git_config_bool_or_int(const char *name, const char *value, int *is_bool)
307 {
308         *is_bool = 1;
309         if (!value)
310                 return 1;
311         if (!*value)
312                 return 0;
313         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
314                 return 1;
315         if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
316                 return 0;
317         *is_bool = 0;
318         return git_config_int(name, value);
319 }
320
321 int git_config_bool(const char *name, const char *value)
322 {
323         int discard;
324         return !!git_config_bool_or_int(name, value, &discard);
325 }
326
327 int git_config_string(const char **dest, const char *var, const char *value)
328 {
329         if (!value)
330                 return config_error_nonbool(var);
331         *dest = xstrdup(value);
332         return 0;
333 }
334
335 int git_default_config(const char *var, const char *value, void *dummy)
336 {
337         /* This needs a better name */
338         if (!strcmp(var, "core.filemode")) {
339                 trust_executable_bit = git_config_bool(var, value);
340                 return 0;
341         }
342
343         if (!strcmp(var, "core.quotepath")) {
344                 quote_path_fully = git_config_bool(var, value);
345                 return 0;
346         }
347
348         if (!strcmp(var, "core.symlinks")) {
349                 has_symlinks = git_config_bool(var, value);
350                 return 0;
351         }
352
353         if (!strcmp(var, "core.ignorecase")) {
354                 ignore_case = git_config_bool(var, value);
355                 return 0;
356         }
357
358         if (!strcmp(var, "core.bare")) {
359                 is_bare_repository_cfg = git_config_bool(var, value);
360                 return 0;
361         }
362
363         if (!strcmp(var, "core.ignorestat")) {
364                 assume_unchanged = git_config_bool(var, value);
365                 return 0;
366         }
367
368         if (!strcmp(var, "core.prefersymlinkrefs")) {
369                 prefer_symlink_refs = git_config_bool(var, value);
370                 return 0;
371         }
372
373         if (!strcmp(var, "core.logallrefupdates")) {
374                 log_all_ref_updates = git_config_bool(var, value);
375                 return 0;
376         }
377
378         if (!strcmp(var, "core.warnambiguousrefs")) {
379                 warn_ambiguous_refs = git_config_bool(var, value);
380                 return 0;
381         }
382
383         if (!strcmp(var, "core.loosecompression")) {
384                 int level = git_config_int(var, value);
385                 if (level == -1)
386                         level = Z_DEFAULT_COMPRESSION;
387                 else if (level < 0 || level > Z_BEST_COMPRESSION)
388                         die("bad zlib compression level %d", level);
389                 zlib_compression_level = level;
390                 zlib_compression_seen = 1;
391                 return 0;
392         }
393
394         if (!strcmp(var, "core.compression")) {
395                 int level = git_config_int(var, value);
396                 if (level == -1)
397                         level = Z_DEFAULT_COMPRESSION;
398                 else if (level < 0 || level > Z_BEST_COMPRESSION)
399                         die("bad zlib compression level %d", level);
400                 core_compression_level = level;
401                 core_compression_seen = 1;
402                 if (!zlib_compression_seen)
403                         zlib_compression_level = level;
404                 return 0;
405         }
406
407         if (!strcmp(var, "core.packedgitwindowsize")) {
408                 int pgsz_x2 = getpagesize() * 2;
409                 packed_git_window_size = git_config_int(var, value);
410
411                 /* This value must be multiple of (pagesize * 2) */
412                 packed_git_window_size /= pgsz_x2;
413                 if (packed_git_window_size < 1)
414                         packed_git_window_size = 1;
415                 packed_git_window_size *= pgsz_x2;
416                 return 0;
417         }
418
419         if (!strcmp(var, "core.packedgitlimit")) {
420                 packed_git_limit = git_config_int(var, value);
421                 return 0;
422         }
423
424         if (!strcmp(var, "core.deltabasecachelimit")) {
425                 delta_base_cache_limit = git_config_int(var, value);
426                 return 0;
427         }
428
429         if (!strcmp(var, "core.autocrlf")) {
430                 if (value && !strcasecmp(value, "input")) {
431                         auto_crlf = -1;
432                         return 0;
433                 }
434                 auto_crlf = git_config_bool(var, value);
435                 return 0;
436         }
437
438         if (!strcmp(var, "core.safecrlf")) {
439                 if (value && !strcasecmp(value, "warn")) {
440                         safe_crlf = SAFE_CRLF_WARN;
441                         return 0;
442                 }
443                 safe_crlf = git_config_bool(var, value);
444                 return 0;
445         }
446
447         if (!strcmp(var, "user.name")) {
448                 if (!value)
449                         return config_error_nonbool(var);
450                 strlcpy(git_default_name, value, sizeof(git_default_name));
451                 if (git_default_email[0])
452                         user_ident_explicitly_given = 1;
453                 return 0;
454         }
455
456         if (!strcmp(var, "user.email")) {
457                 if (!value)
458                         return config_error_nonbool(var);
459                 strlcpy(git_default_email, value, sizeof(git_default_email));
460                 if (git_default_name[0])
461                         user_ident_explicitly_given = 1;
462                 return 0;
463         }
464
465         if (!strcmp(var, "i18n.commitencoding"))
466                 return git_config_string(&git_commit_encoding, var, value);
467
468         if (!strcmp(var, "i18n.logoutputencoding"))
469                 return git_config_string(&git_log_output_encoding, var, value);
470
471         if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
472                 pager_use_color = git_config_bool(var,value);
473                 return 0;
474         }
475
476         if (!strcmp(var, "core.pager"))
477                 return git_config_string(&pager_program, var, value);
478
479         if (!strcmp(var, "core.editor"))
480                 return git_config_string(&editor_program, var, value);
481
482         if (!strcmp(var, "core.excludesfile"))
483                 return git_config_string(&excludes_file, var, value);
484
485         if (!strcmp(var, "core.whitespace")) {
486                 if (!value)
487                         return config_error_nonbool(var);
488                 whitespace_rule_cfg = parse_whitespace_rule(value);
489                 return 0;
490         }
491         if (!strcmp(var, "branch.autosetupmerge")) {
492                 if (value && !strcasecmp(value, "always")) {
493                         git_branch_track = BRANCH_TRACK_ALWAYS;
494                         return 0;
495                 }
496                 git_branch_track = git_config_bool(var, value);
497                 return 0;
498         }
499         if (!strcmp(var, "branch.autosetuprebase")) {
500                 if (!value)
501                         return config_error_nonbool(var);
502                 else if (!strcmp(value, "never"))
503                         autorebase = AUTOREBASE_NEVER;
504                 else if (!strcmp(value, "local"))
505                         autorebase = AUTOREBASE_LOCAL;
506                 else if (!strcmp(value, "remote"))
507                         autorebase = AUTOREBASE_REMOTE;
508                 else if (!strcmp(value, "always"))
509                         autorebase = AUTOREBASE_ALWAYS;
510                 else
511                         return error("Malformed value for %s", var);
512                 return 0;
513         }
514
515         /* Add other config variables here and to Documentation/config.txt. */
516         return 0;
517 }
518
519 int git_config_from_file(config_fn_t fn, const char *filename, void *data)
520 {
521         int ret;
522         FILE *f = fopen(filename, "r");
523
524         ret = -1;
525         if (f) {
526                 config_file = f;
527                 config_file_name = filename;
528                 config_linenr = 1;
529                 config_file_eof = 0;
530                 ret = git_parse_file(fn, data);
531                 fclose(f);
532                 config_file_name = NULL;
533         }
534         return ret;
535 }
536
537 const char *git_etc_gitconfig(void)
538 {
539         static const char *system_wide;
540         if (!system_wide) {
541                 system_wide = ETC_GITCONFIG;
542                 if (!is_absolute_path(system_wide)) {
543                         /* interpret path relative to exec-dir */
544                         struct strbuf d = STRBUF_INIT;
545                         strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
546                         system_wide = strbuf_detach(&d, NULL);
547                 }
548         }
549         return system_wide;
550 }
551
552 int git_env_bool(const char *k, int def)
553 {
554         const char *v = getenv(k);
555         return v ? git_config_bool(k, v) : def;
556 }
557
558 int git_config_system(void)
559 {
560         return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
561 }
562
563 int git_config_global(void)
564 {
565         return !git_env_bool("GIT_CONFIG_NOGLOBAL", 0);
566 }
567
568 int git_config(config_fn_t fn, void *data)
569 {
570         int ret = 0;
571         char *repo_config = NULL;
572         const char *home = NULL, *filename;
573
574         /* $GIT_CONFIG makes git read _only_ the given config file,
575          * $GIT_CONFIG_LOCAL will make it process it in addition to the
576          * global config file, the same way it would the per-repository
577          * config file otherwise. */
578         filename = getenv(CONFIG_ENVIRONMENT);
579         if (!filename) {
580                 if (git_config_system() && !access(git_etc_gitconfig(), R_OK))
581                         ret += git_config_from_file(fn, git_etc_gitconfig(),
582                                 data);
583                 home = getenv("HOME");
584                 filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
585                 if (!filename)
586                         filename = repo_config = xstrdup(git_path("config"));
587         }
588
589         if (git_config_global() && home) {
590                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
591                 if (!access(user_config, R_OK))
592                         ret = git_config_from_file(fn, user_config, data);
593                 free(user_config);
594         }
595
596         ret += git_config_from_file(fn, filename, data);
597         free(repo_config);
598         return ret;
599 }
600
601 /*
602  * Find all the stuff for git_config_set() below.
603  */
604
605 #define MAX_MATCHES 512
606
607 static struct {
608         int baselen;
609         char* key;
610         int do_not_match;
611         regex_t* value_regex;
612         int multi_replace;
613         size_t offset[MAX_MATCHES];
614         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
615         int seen;
616 } store;
617
618 static int matches(const char* key, const char* value)
619 {
620         return !strcmp(key, store.key) &&
621                 (store.value_regex == NULL ||
622                  (store.do_not_match ^
623                   !regexec(store.value_regex, value, 0, NULL, 0)));
624 }
625
626 static int store_aux(const char* key, const char* value, void *cb)
627 {
628         const char *ep;
629         size_t section_len;
630
631         switch (store.state) {
632         case KEY_SEEN:
633                 if (matches(key, value)) {
634                         if (store.seen == 1 && store.multi_replace == 0) {
635                                 warning("%s has multiple values", key);
636                         } else if (store.seen >= MAX_MATCHES) {
637                                 error("too many matches for %s", key);
638                                 return 1;
639                         }
640
641                         store.offset[store.seen] = ftell(config_file);
642                         store.seen++;
643                 }
644                 break;
645         case SECTION_SEEN:
646                 /*
647                  * What we are looking for is in store.key (both
648                  * section and var), and its section part is baselen
649                  * long.  We found key (again, both section and var).
650                  * We would want to know if this key is in the same
651                  * section as what we are looking for.  We already
652                  * know we are in the same section as what should
653                  * hold store.key.
654                  */
655                 ep = strrchr(key, '.');
656                 section_len = ep - key;
657
658                 if ((section_len != store.baselen) ||
659                     memcmp(key, store.key, section_len+1)) {
660                         store.state = SECTION_END_SEEN;
661                         break;
662                 }
663
664                 /*
665                  * Do not increment matches: this is no match, but we
666                  * just made sure we are in the desired section.
667                  */
668                 store.offset[store.seen] = ftell(config_file);
669                 /* fallthru */
670         case SECTION_END_SEEN:
671         case START:
672                 if (matches(key, value)) {
673                         store.offset[store.seen] = ftell(config_file);
674                         store.state = KEY_SEEN;
675                         store.seen++;
676                 } else {
677                         if (strrchr(key, '.') - key == store.baselen &&
678                               !strncmp(key, store.key, store.baselen)) {
679                                         store.state = SECTION_SEEN;
680                                         store.offset[store.seen] = ftell(config_file);
681                         }
682                 }
683         }
684         return 0;
685 }
686
687 static int write_error(const char *filename)
688 {
689         error("failed to write new configuration file %s", filename);
690
691         /* Same error code as "failed to rename". */
692         return 4;
693 }
694
695 static int store_write_section(int fd, const char* key)
696 {
697         const char *dot;
698         int i, success;
699         struct strbuf sb;
700
701         strbuf_init(&sb, 0);
702         dot = memchr(key, '.', store.baselen);
703         if (dot) {
704                 strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
705                 for (i = dot - key + 1; i < store.baselen; i++) {
706                         if (key[i] == '"' || key[i] == '\\')
707                                 strbuf_addch(&sb, '\\');
708                         strbuf_addch(&sb, key[i]);
709                 }
710                 strbuf_addstr(&sb, "\"]\n");
711         } else {
712                 strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
713         }
714
715         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
716         strbuf_release(&sb);
717
718         return success;
719 }
720
721 static int store_write_pair(int fd, const char* key, const char* value)
722 {
723         int i, success;
724         int length = strlen(key + store.baselen + 1);
725         const char *quote = "";
726         struct strbuf sb;
727
728         /*
729          * Check to see if the value needs to be surrounded with a dq pair.
730          * Note that problematic characters are always backslash-quoted; this
731          * check is about not losing leading or trailing SP and strings that
732          * follow beginning-of-comment characters (i.e. ';' and '#') by the
733          * configuration parser.
734          */
735         if (value[0] == ' ')
736                 quote = "\"";
737         for (i = 0; value[i]; i++)
738                 if (value[i] == ';' || value[i] == '#')
739                         quote = "\"";
740         if (i && value[i - 1] == ' ')
741                 quote = "\"";
742
743         strbuf_init(&sb, 0);
744         strbuf_addf(&sb, "\t%.*s = %s",
745                     length, key + store.baselen + 1, quote);
746
747         for (i = 0; value[i]; i++)
748                 switch (value[i]) {
749                 case '\n':
750                         strbuf_addstr(&sb, "\\n");
751                         break;
752                 case '\t':
753                         strbuf_addstr(&sb, "\\t");
754                         break;
755                 case '"':
756                 case '\\':
757                         strbuf_addch(&sb, '\\');
758                 default:
759                         strbuf_addch(&sb, value[i]);
760                         break;
761                 }
762         strbuf_addf(&sb, "%s\n", quote);
763
764         success = write_in_full(fd, sb.buf, sb.len) == sb.len;
765         strbuf_release(&sb);
766
767         return success;
768 }
769
770 static ssize_t find_beginning_of_line(const char* contents, size_t size,
771         size_t offset_, int* found_bracket)
772 {
773         size_t equal_offset = size, bracket_offset = size;
774         ssize_t offset;
775
776 contline:
777         for (offset = offset_-2; offset > 0
778                         && contents[offset] != '\n'; offset--)
779                 switch (contents[offset]) {
780                         case '=': equal_offset = offset; break;
781                         case ']': bracket_offset = offset; break;
782                 }
783         if (offset > 0 && contents[offset-1] == '\\') {
784                 offset_ = offset;
785                 goto contline;
786         }
787         if (bracket_offset < equal_offset) {
788                 *found_bracket = 1;
789                 offset = bracket_offset+1;
790         } else
791                 offset++;
792
793         return offset;
794 }
795
796 int git_config_set(const char* key, const char* value)
797 {
798         return git_config_set_multivar(key, value, NULL, 0);
799 }
800
801 /*
802  * If value==NULL, unset in (remove from) config,
803  * if value_regex!=NULL, disregard key/value pairs where value does not match.
804  * if multi_replace==0, nothing, or only one matching key/value is replaced,
805  *     else all matching key/values (regardless how many) are removed,
806  *     before the new pair is written.
807  *
808  * Returns 0 on success.
809  *
810  * This function does this:
811  *
812  * - it locks the config file by creating ".git/config.lock"
813  *
814  * - it then parses the config using store_aux() as validator to find
815  *   the position on the key/value pair to replace. If it is to be unset,
816  *   it must be found exactly once.
817  *
818  * - the config file is mmap()ed and the part before the match (if any) is
819  *   written to the lock file, then the changed part and the rest.
820  *
821  * - the config file is removed and the lock file rename()d to it.
822  *
823  */
824 int git_config_set_multivar(const char* key, const char* value,
825         const char* value_regex, int multi_replace)
826 {
827         int i, dot;
828         int fd = -1, in_fd;
829         int ret;
830         char* config_filename;
831         struct lock_file *lock = NULL;
832         const char* last_dot = strrchr(key, '.');
833
834         config_filename = getenv(CONFIG_ENVIRONMENT);
835         if (!config_filename) {
836                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
837                 if (!config_filename)
838                         config_filename  = git_path("config");
839         }
840         config_filename = xstrdup(config_filename);
841
842         /*
843          * Since "key" actually contains the section name and the real
844          * key name separated by a dot, we have to know where the dot is.
845          */
846
847         if (last_dot == NULL) {
848                 error("key does not contain a section: %s", key);
849                 ret = 2;
850                 goto out_free;
851         }
852         store.baselen = last_dot - key;
853
854         store.multi_replace = multi_replace;
855
856         /*
857          * Validate the key and while at it, lower case it for matching.
858          */
859         store.key = xmalloc(strlen(key) + 1);
860         dot = 0;
861         for (i = 0; key[i]; i++) {
862                 unsigned char c = key[i];
863                 if (c == '.')
864                         dot = 1;
865                 /* Leave the extended basename untouched.. */
866                 if (!dot || i > store.baselen) {
867                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
868                                 error("invalid key: %s", key);
869                                 free(store.key);
870                                 ret = 1;
871                                 goto out_free;
872                         }
873                         c = tolower(c);
874                 } else if (c == '\n') {
875                         error("invalid key (newline): %s", key);
876                         free(store.key);
877                         ret = 1;
878                         goto out_free;
879                 }
880                 store.key[i] = c;
881         }
882         store.key[i] = 0;
883
884         /*
885          * The lock serves a purpose in addition to locking: the new
886          * contents of .git/config will be written into it.
887          */
888         lock = xcalloc(sizeof(struct lock_file), 1);
889         fd = hold_lock_file_for_update(lock, config_filename, 0);
890         if (fd < 0) {
891                 error("could not lock config file %s", config_filename);
892                 free(store.key);
893                 ret = -1;
894                 goto out_free;
895         }
896
897         /*
898          * If .git/config does not exist yet, write a minimal version.
899          */
900         in_fd = open(config_filename, O_RDONLY);
901         if ( in_fd < 0 ) {
902                 free(store.key);
903
904                 if ( ENOENT != errno ) {
905                         error("opening %s: %s", config_filename,
906                               strerror(errno));
907                         ret = 3; /* same as "invalid config file" */
908                         goto out_free;
909                 }
910                 /* if nothing to unset, error out */
911                 if (value == NULL) {
912                         ret = 5;
913                         goto out_free;
914                 }
915
916                 store.key = (char*)key;
917                 if (!store_write_section(fd, key) ||
918                     !store_write_pair(fd, key, value))
919                         goto write_err_out;
920         } else {
921                 struct stat st;
922                 char* contents;
923                 size_t contents_sz, copy_begin, copy_end;
924                 int i, new_line = 0;
925
926                 if (value_regex == NULL)
927                         store.value_regex = NULL;
928                 else {
929                         if (value_regex[0] == '!') {
930                                 store.do_not_match = 1;
931                                 value_regex++;
932                         } else
933                                 store.do_not_match = 0;
934
935                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
936                         if (regcomp(store.value_regex, value_regex,
937                                         REG_EXTENDED)) {
938                                 error("invalid pattern: %s", value_regex);
939                                 free(store.value_regex);
940                                 ret = 6;
941                                 goto out_free;
942                         }
943                 }
944
945                 store.offset[0] = 0;
946                 store.state = START;
947                 store.seen = 0;
948
949                 /*
950                  * After this, store.offset will contain the *end* offset
951                  * of the last match, or remain at 0 if no match was found.
952                  * As a side effect, we make sure to transform only a valid
953                  * existing config file.
954                  */
955                 if (git_config_from_file(store_aux, config_filename, NULL)) {
956                         error("invalid config file %s", config_filename);
957                         free(store.key);
958                         if (store.value_regex != NULL) {
959                                 regfree(store.value_regex);
960                                 free(store.value_regex);
961                         }
962                         ret = 3;
963                         goto out_free;
964                 }
965
966                 free(store.key);
967                 if (store.value_regex != NULL) {
968                         regfree(store.value_regex);
969                         free(store.value_regex);
970                 }
971
972                 /* if nothing to unset, or too many matches, error out */
973                 if ((store.seen == 0 && value == NULL) ||
974                                 (store.seen > 1 && multi_replace == 0)) {
975                         ret = 5;
976                         goto out_free;
977                 }
978
979                 fstat(in_fd, &st);
980                 contents_sz = xsize_t(st.st_size);
981                 contents = xmmap(NULL, contents_sz, PROT_READ,
982                         MAP_PRIVATE, in_fd, 0);
983                 close(in_fd);
984
985                 if (store.seen == 0)
986                         store.seen = 1;
987
988                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
989                         if (store.offset[i] == 0) {
990                                 store.offset[i] = copy_end = contents_sz;
991                         } else if (store.state != KEY_SEEN) {
992                                 copy_end = store.offset[i];
993                         } else
994                                 copy_end = find_beginning_of_line(
995                                         contents, contents_sz,
996                                         store.offset[i]-2, &new_line);
997
998                         if (copy_end > 0 && contents[copy_end-1] != '\n')
999                                 new_line = 1;
1000
1001                         /* write the first part of the config */
1002                         if (copy_end > copy_begin) {
1003                                 if (write_in_full(fd, contents + copy_begin,
1004                                                   copy_end - copy_begin) <
1005                                     copy_end - copy_begin)
1006                                         goto write_err_out;
1007                                 if (new_line &&
1008                                     write_in_full(fd, "\n", 1) != 1)
1009                                         goto write_err_out;
1010                         }
1011                         copy_begin = store.offset[i];
1012                 }
1013
1014                 /* write the pair (value == NULL means unset) */
1015                 if (value != NULL) {
1016                         if (store.state == START) {
1017                                 if (!store_write_section(fd, key))
1018                                         goto write_err_out;
1019                         }
1020                         if (!store_write_pair(fd, key, value))
1021                                 goto write_err_out;
1022                 }
1023
1024                 /* write the rest of the config */
1025                 if (copy_begin < contents_sz)
1026                         if (write_in_full(fd, contents + copy_begin,
1027                                           contents_sz - copy_begin) <
1028                             contents_sz - copy_begin)
1029                                 goto write_err_out;
1030
1031                 munmap(contents, contents_sz);
1032         }
1033
1034         if (commit_lock_file(lock) < 0) {
1035                 error("could not commit config file %s", config_filename);
1036                 ret = 4;
1037                 goto out_free;
1038         }
1039
1040         /*
1041          * lock is committed, so don't try to roll it back below.
1042          * NOTE: Since lockfile.c keeps a linked list of all created
1043          * lock_file structures, it isn't safe to free(lock).  It's
1044          * better to just leave it hanging around.
1045          */
1046         lock = NULL;
1047         ret = 0;
1048
1049 out_free:
1050         if (lock)
1051                 rollback_lock_file(lock);
1052         free(config_filename);
1053         return ret;
1054
1055 write_err_out:
1056         ret = write_error(lock->filename);
1057         goto out_free;
1058
1059 }
1060
1061 static int section_name_match (const char *buf, const char *name)
1062 {
1063         int i = 0, j = 0, dot = 0;
1064         for (; buf[i] && buf[i] != ']'; i++) {
1065                 if (!dot && isspace(buf[i])) {
1066                         dot = 1;
1067                         if (name[j++] != '.')
1068                                 break;
1069                         for (i++; isspace(buf[i]); i++)
1070                                 ; /* do nothing */
1071                         if (buf[i] != '"')
1072                                 break;
1073                         continue;
1074                 }
1075                 if (buf[i] == '\\' && dot)
1076                         i++;
1077                 else if (buf[i] == '"' && dot) {
1078                         for (i++; isspace(buf[i]); i++)
1079                                 ; /* do_nothing */
1080                         break;
1081                 }
1082                 if (buf[i] != name[j++])
1083                         break;
1084         }
1085         return (buf[i] == ']' && name[j] == 0);
1086 }
1087
1088 /* if new_name == NULL, the section is removed instead */
1089 int git_config_rename_section(const char *old_name, const char *new_name)
1090 {
1091         int ret = 0, remove = 0;
1092         char *config_filename;
1093         struct lock_file *lock = xcalloc(sizeof(struct lock_file), 1);
1094         int out_fd;
1095         char buf[1024];
1096
1097         config_filename = getenv(CONFIG_ENVIRONMENT);
1098         if (!config_filename) {
1099                 config_filename = getenv(CONFIG_LOCAL_ENVIRONMENT);
1100                 if (!config_filename)
1101                         config_filename  = git_path("config");
1102         }
1103         config_filename = xstrdup(config_filename);
1104         out_fd = hold_lock_file_for_update(lock, config_filename, 0);
1105         if (out_fd < 0) {
1106                 ret = error("could not lock config file %s", config_filename);
1107                 goto out;
1108         }
1109
1110         if (!(config_file = fopen(config_filename, "rb"))) {
1111                 /* no config file means nothing to rename, no error */
1112                 goto unlock_and_out;
1113         }
1114
1115         while (fgets(buf, sizeof(buf), config_file)) {
1116                 int i;
1117                 int length;
1118                 for (i = 0; buf[i] && isspace(buf[i]); i++)
1119                         ; /* do nothing */
1120                 if (buf[i] == '[') {
1121                         /* it's a section */
1122                         if (section_name_match (&buf[i+1], old_name)) {
1123                                 ret++;
1124                                 if (new_name == NULL) {
1125                                         remove = 1;
1126                                         continue;
1127                                 }
1128                                 store.baselen = strlen(new_name);
1129                                 if (!store_write_section(out_fd, new_name)) {
1130                                         ret = write_error(lock->filename);
1131                                         goto out;
1132                                 }
1133                                 continue;
1134                         }
1135                         remove = 0;
1136                 }
1137                 if (remove)
1138                         continue;
1139                 length = strlen(buf);
1140                 if (write_in_full(out_fd, buf, length) != length) {
1141                         ret = write_error(lock->filename);
1142                         goto out;
1143                 }
1144         }
1145         fclose(config_file);
1146  unlock_and_out:
1147         if (commit_lock_file(lock) < 0)
1148                 ret = error("could not commit config file %s", config_filename);
1149  out:
1150         free(config_filename);
1151         return ret;
1152 }
1153
1154 /*
1155  * Call this to report error for your variable that should not
1156  * get a boolean value (i.e. "[my] var" means "true").
1157  */
1158 int config_error_nonbool(const char *var)
1159 {
1160         return error("Missing value for '%s'", var);
1161 }